timer.c 1.3 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * (C) Copyright 2002
  4. * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
  5. * Marius Groeger <mgroeger@sysgo.de>
  6. *
  7. * (C) Copyright 2002
  8. * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
  9. * Alex Zuepke <azu@sysgo.de>
  10. *
  11. * (C) Copyright 2002
  12. * Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
  13. *
  14. * (C) Copyright 2009
  15. * Ilya Yanok, Emcraft Systems Ltd, <yanok@emcraft.com>
  16. *
  17. * (C) Copyright 2009 DENX Software Engineering
  18. * Author: John Rigby <jrigby@gmail.com>
  19. * Add support for MX25
  20. */
  21. #include <common.h>
  22. #include <init.h>
  23. #include <asm/io.h>
  24. #include <asm/arch/imx-regs.h>
  25. #include <asm/ptrace.h>
  26. /* nothing really to do with interrupts, just starts up a counter. */
  27. /* The 32KHz 32-bit timer overruns in 134217 seconds */
  28. int timer_init(void)
  29. {
  30. int i;
  31. struct gpt_regs *gpt = (struct gpt_regs *)IMX_GPT1_BASE;
  32. struct ccm_regs *ccm = (struct ccm_regs *)IMX_CCM_BASE;
  33. /* setup GP Timer 1 */
  34. writel(GPT_CTRL_SWR, &gpt->ctrl);
  35. writel(readl(&ccm->cgr1) | CCM_CGR1_GPT1, &ccm->cgr1);
  36. for (i = 0; i < 100; i++)
  37. writel(0, &gpt->ctrl); /* We have no udelay by now */
  38. writel(0, &gpt->pre); /* prescaler = 1 */
  39. /* Freerun Mode, 32KHz input */
  40. writel(readl(&gpt->ctrl) | GPT_CTRL_CLKSOURCE_32 | GPT_CTRL_FRR,
  41. &gpt->ctrl);
  42. writel(readl(&gpt->ctrl) | GPT_CTRL_TEN, &gpt->ctrl);
  43. return 0;
  44. }